<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			*{
				margin: 0;
				padding: 0;
			}
			#wrap{
				width: 300px;
				height: 300px;
				margin: 100px auto;
				background: pink;
				opacity: 0.1;
			}
			#inner{
				width: 100px;
				height: 100px;
				background: deeppink;
			}
		</style>
	</head>
	<body>
		<div id="wrap">
			<div id="inner">
				inner
			</div>
		</div>
	</body>
</html>
